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When to Give Your Newborn Baby Formulahttp://www.slate.com/blogs/expecting_better/2013/09/13/when_to_give_your_newborn_baby_formula_the_first_big_decision_i_had_to_make.html
<p>This is goodbye! I hope you enjoyed the blog, and if you have more questions, check out <a href="http://www.amazon.com/Expecting-Better-Conventional-Pregnancy-Wrong-/dp/1594204756/ref=sr_1_1?s=books&amp;ie=UTF8&amp;qid=1379086822&amp;sr=1-1&amp;keywords=expecting+better">the whole book</a>, which covers many more topics: epidurals, home births, weight gain, and hot yoga, among others.</p>
<p>My book stops at the delivery room, but as many people have pointed out to me in emails, the decisions definitely do not. As we part, I just wanted to share with you the first big one I faced not as a pregnant woman but as a new mom. My daughter was born at 7 pounds 12 ounces, and since she arrived first thing in the morning, we got two nights in the hospital. On the second night they took her away for some kind of test and came back to inform me that she had lost 11 percent of her body weight. Since the hospital’s limit was 10 percent, I would have to start giving her formula or—and this is a direct quote—“She might not be able to go home with you.”</p>
<p>The data-driven part of me thought, “Wait a minute. Aren’t 11 percent and 10 percent basically the same?” The hormone-crazed postpartum mom part thought, “I will do anything under the sun to take my baby home.” And so I found myself taping together some kind of elaborate tubing system so Penelope would think she was nursing but really be getting formula.</p>
<p>I remember thinking to myself, “I really should research this weight-loss issue.” But then they did let me take her home, and I completely forgot about the issue until months later a friend told me that she experienced the same thing. It seems to be a pretty common situation—another friend was told to save all the diapers her kid produced to weigh them. So what’s the deal?</p>
<p>The big concern with excess weight loss is it could reflect dehydration (if the baby isn’t getting enough milk), and this can have very bad consequences, like a stroke. This is quite rare but has been observed in <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1721293/pdf/v085p0F145a.pdf">case studies</a>. The babies in these studies have lost a lot of weight—say, 20 percent by eight days after birth—but the broad concerns are the same even if your baby hasn’t lost as much.</p>
<p>In terms of what is normal: Based on <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1763225/pdf/v088p0F472.pdf">one study</a>, the average breast-fed baby will lose about 7 percent of his or her body weight in the first three days. Five percent of babies will lose 12 percent or more. Formula-fed babies lose much less. By drawing the line at 10 percent for encouraging supplementation, as many hospitals do, about 10 percent of breast-fed babies will fall below the cutoff (and less than 2 percent of formula-fed babies).</p>
<p>Of course, an equally important issue—and one I also had not researched—was whether giving some formula early on would impact my ability to successfully breast-feed later. In fact, it seems like the answer is no—this based <a href="http://www.ncbi.nlm.nih.gov/pubmed/23669513">on one recent</a> randomized trial, and one <a href="http://www.ncbi.nlm.nih.gov/pubmed/3883306">older one</a>.</p>
<p>So had I known all of this at 3 a.m. on the day after delivery, what would I have done? I still would have gone ahead with the formula. While 10 percent (or 11 in my child’s case) weight loss isn’t a real reason to panic, in principle there are serious consequences, and 10 percent is on the high end. And there is really no downside to a small amount of formula at this point. I also would have paid much more attention to how much my daughter was peeing—since dehydration will show up in reduced urine output, that is an important sign alongside weight loss that something should be done.</p>
<p>Fortunately, by the time we got home, my husband had already set up a computer in the baby’s room to record all wet and dirty diapers, nursing time, milk intake, and sleep schedules. The real data-driven decisions were just beginning.</p>Fri, 13 Sep 2013 16:30:41 GMThttp://www.slate.com/blogs/expecting_better/2013/09/13/when_to_give_your_newborn_baby_formula_the_first_big_decision_i_had_to_make.htmlEmily Oster2013-09-13T16:30:41ZDouble XWhen to Give Your Newborn Baby Formula238130913001parentingbreastfeedingEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/09/13/when_to_give_your_newborn_baby_formula_the_first_big_decision_i_had_to_make.htmlfalsefalsefalseWhen should you give your newborn baby formula?When to Give Your Newborn Baby FormulaPhoto by Vadym Zaitsev/ShutterstockI Wrote That It's OK to Drink While Pregnant. Everyone Freaked Out. Here's Why I'm Right.http://www.slate.com/blogs/expecting_better/2013/09/11/drinking_during_pregnancy_what_the_experts_don_t_tell_you.html
<p>When I was pregnant, I wondered, as many women do: Can I have a drink? It is well-known that drinking to excess during pregnancy is dangerous, and perhaps less well known but still true, that even one or two episodes of binge drinking can be harmful. But what about an occasional glass of wine with dinner?</p>
<p>Expert opinions on this differ. <a href="http://www.amazon.com/gp/product/0761148574/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=0761148574&amp;linkCode=as2&amp;tag=slatmaga-20"><em>What to Expect When You’re Expecting</em></a> says no alcohol. <a href="http://www.amazon.com/gp/product/0399529896/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=0399529896&amp;linkCode=as2&amp;tag=slatmaga-20"><em>Panic-Free Pregnancy</em></a> says an occasional drink is fine. <a href="http://www.ncbi.nlm.nih.gov/pubmed/21769028">A 2010 survey</a> asked obstetricians, “How much alcohol can a pregnant woman consume without risk of adverse pregnancy outcomes?” Sixty percent of the OBs said none, but the other 40 percent said some alcohol was fine. The American Congress of Obstetricians and Gynecologists (ACOG) says no amount of alcohol has been shown to be safe, but the U.K. equivalent (the Royal College of Obstetricians and Gynecologists) <a href="http://www.rcog.org.uk/files/rcog-corp/Alcohol%20and%20Pregnancy.pdf">says that</a> while not drinking is the safest option, “Small amounts of alcohol during pregnancy have not been shown to be harmful.”</p>
<p>My obstetrician said a few drinks a week was fine. But as with everything else, amid this disagreement, I needed to go to the data myself.</p>
<p>I reviewed many, many studies, but I focused in on ones that compare women who drank lightly or occasionally during pregnancy to those who abstained. The best of these studies are ones that separate women into several groups—for example: no alcohol, a few drinks a week, one drink a day, more than one drink a day—and that limit the focus to women who say they never had a binge drinking episode. With these parameters, we can really hone in on the question of interest: What is the impact of having an occasional drink, assuming that you never overdo it?&nbsp;</p>
<p>I summarize two studies in detail <a href="http://www.amazon.com/dp/1594204756/?tag=slatmaga-20">in my book</a>: one looking at <a href="http://www.ncbi.nlm.nih.gov/pubmed/20528867">alcohol consumption by pregnant women and behavior</a> problems for the resulting children up to age 14 and <a href="http://www.ncbi.nlm.nih.gov/pubmed/16842939">one looking</a> at alcohol in pregnancy and test performance at age 14.&nbsp; Both show no difference between the children of women who abstain and those who drink up to a drink a day. I summarize two others in less detail: one looking at <a href="http://www.ncbi.nlm.nih.gov/pubmed/18670372">IQ scores at age 8</a> and a more recent one looking at <a href="http://www.ncbi.nlm.nih.gov/pubmed/22712874">IQ scores at age 5</a>. These also demonstrate no impact of light drinking on test scores.&nbsp;</p>
<p>I argue that based on this data, many women may feel comfortable with an occasional glass of wine—even up to one a day—in later trimesters. (More caution in the first trimester—no more than two drinks a week—because of some evidence of miscarriage risk.)</p>
<p>Although this discussion takes up only a small share of the book, it has garnered the loudest reaction, much of it outrage. NOFAS, a fetal alcohol syndrome advocacy group, issued <a href="http://www.nofas.org/2013/08/16/emily_oster/">a press release</a> even before the book came out saying I was harmful and irresponsible. <a href="http://www.amazon.com/Expecting-Better-Conventional-Pregnancy-Wrong/product-reviews/1594204756/ref=dp_top_cm_cr_acr_txt?showViewpoints=1">Amazon reviews</a> of the book—at least some of them by people who explicitly said they would never read it—attacked me and anyone who had a drink during pregnancy as an alcoholic. One commented on my daughter: “Emily Oster claims that her 2-year old daughter is perfectly healthy, yet the full impact of the alcohol exposure on her child will not be evident until the adolescent years.”</p>
<p>The president of ACOG has vehemently disagreed with me, saying in a radio interview about occasional drinking that alcohol in pregnancy is more dangerous than heroin or cocaine. Of course, there has been occasional public agreement from OBs (and much more private agreement).</p>
<p>Some of the arguments made in response to the book are tangential. Commenters wish that there was more in the book about the dangers of fetal alcohol syndrome, more discussion of the risks of binge drinking. I spend only a page on this, since it is not the question I believe most readers of the book are asking.&nbsp;</p>
<p>Some of them are philosophical. People ask, “Why take the risk?” since there is no benefit to the baby. But this ignores the fact that we are always making choices that could carry some risk and have no benefit to the baby. Driving in a car carries some risk to your baby, and your fetus does not benefit from that vacation you took. Or they ask, “Is it so hard to give up drinking for nine months?” The answer is, of course, no, but because you might enjoy the occasional beer, it seems worth at least asking the question about the risks.</p>
<p>Then there is the criticism that I cherry-picked studies to fit the story. This certainly isn’t the case; the fact that the book doesn’t summarize all 23,000 studies in PubMed on alcohol in pregnancy reflects the desire to identify the most reliable and largest and present those. Still, it’s reasonable to ask whether there are studies that I missed that tell a different story.</p>
<p>One fact that has been cited to me a number of times, including by the ACOG president, is: “One in 7 children with fetal alcohol syndrome had a mother who drank one to eight drinks per week in the first trimester.” The implication is that even light drinking early on (which would be much closer to one than eight drinks) is dangerous. But this claim doesn’t come from a study; it comes from a statement made in a <a href="http://www.ncbi.nlm.nih.gov/pubmed/23164118">letter to the editor</a>, and it’s therefore impossible to evaluate critically. One to eight drinks a week could mean eight drinks on one night, for instance, and that is known to be dangerous.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/23442183">Another study</a> that has been mentioned prominently relates prenatal alcohol exposure to behavior problems in young adulthood. Although <a href="http://www.neurodevnet.ca/news/researchers-mark-international-fasd-awareness-day-strong-response-emily-oster-book">some</a> have suggested that this paper identifies impacts of having one drink per day, the analysis actually relates behavior problems to a measure of average daily intake—which includes people having more than that, sometimes a lot more. It’s true that some people evaluated in this study drink lightly, but others do not, and by lumping them together it is very difficult to draw conclusions about the light drinkers.</p>
<p>There is a much more technically <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0049407">complex study</a> that I certainly would have included in the book if it had come out in time. It shows that light maternal drinking is associated with small IQ decreases for people with some particular genetic variants. Light maternal drinking is also associated with small IQ increases in people with some other genetic variants. This suggests that further studies may be useful in evaluating genetic risks, although it doesn’t provide a lot of guidance at this time.</p>
<p>The bottom line is that the criticism fails to identify studies that have the features we would want: a population that is never binge drinking and a data analysis that looks separately at women who drink lightly and those who drink more. In the book I discuss <a href="http://www.ncbi.nlm.nih.gov/pubmed/11483844">one study</a> like this, which does argue there are impacts on behavior at one drink per day, but the study fails to adjust for differences across groups, like whether the father lives at home or if there was prenatal cocaine use, among other things.</p>
<p>Like alcohol, Tylenol, caffeine, and anti-nausea drugs like Zofran are substances that—in moderation—are thought to be safe during pregnancy. But they are also substances that in excessive doses could be dangerous. Some women decide that they will therefore avoid them altogether because they cannot be sure. And many women, seeing the evidence in the book on alcohol, will still choose to avoid it.&nbsp;</p>
<p>But others will see the data, like the data on caffeine or Tylenol, and choose to have an occasional drink, as I did. The value of the data is not that it leads us all to the same choice, just that it introduces a concrete way to make that choice.</p>Wed, 11 Sep 2013 17:57:00 GMThttp://www.slate.com/blogs/expecting_better/2013/09/11/drinking_during_pregnancy_what_the_experts_don_t_tell_you.htmlEmily Oster2013-09-11T17:57:00ZDouble XI Wrote That It's OK to Drink While Pregnant. Everyone Freaked Out. Here's Why I'm Right.238130911001pregnancyFamilyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/09/11/drinking_during_pregnancy_what_the_experts_don_t_tell_you.htmlfalsefalsefalseWhat the experts don't tell you about drinking and pregnancy.I Wrote That It's OK to Drink While Pregnant. Everyone Freaked Out. Here's Why I'm Right.Photo by Kati Neudert/ShutterstockAllowedPlease Can I Have a Turkey Sandwich and Sleep on My Back While Pregnant?http://www.slate.com/blogs/expecting_better/2013/09/06/deli_meats_and_sleeping_on_your_back_while_pregnant_are_either_ok.html
<p>More great reader questions this week. Here are some answers.</p>
<p><strong>From Deli Meat Lover:</strong></p>
<p><em>Are all deli meats a no-go? Or can I continue to eat fancy soppressata sandwiches?</em></p>
<p>The place to start on this is to figure out why deli meats are off limits. The answer is listeria, a very dangerous foodborne illness. Listeria grows well at room temperature, so things like deli meats that sit around in display cases for a long time can be susceptible. It’s very clear that you want to avoid listeria; it can cause miscarriage and stillbirth, and pregnant women are especially susceptible.</p>
<p>What is less clear is how to avoid it. Listeria is rare, which is reassuring, but it’s also hard to avoid. Outbreaks crop up at random—in the last couple of years there were large outbreaks in cantaloupe and celery, for example. If you took what would seem like an obvious approach—avoid everything that has caused known outbreaks in the last 10 years, say—you would put deli turkey on your list, but also bean sprouts, chicken, celery, and cantaloupe.</p>
<p>You can certainly avoid all of these foods, although you don’t know if listeria will crop up next in something else. Another approach is to avoid the foods that contribute to a large share of infections. That list would be pretty short: <a href="http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6222a4.htm?s_cid=mm6222a4_w">between 2009 and 2011</a>, raw milk cheese caused 50 percent of outbreaks with known cause, and no other source accounted for more than one outbreak.</p>
<p>There has been one outbreak in the past 15 years due to ham (the closest outbreak source to soppressata). With those numbers, I would get the sandwich.</p>
<p><strong>From Chrissy:</strong></p>
<p><em>I'm about halfway through my pregnancy and wondering about sleeping while pregnant: Does it really matter how I sleep? I often wake up on my back or even (more regularly) on my stomach. Do I need to barricade myself into sleeping on my left side only? Can I squish the baby when I roll onto my stomach?</em></p>
<p>First, let me assure you that you will not squish the baby on your stomach. If you’re halfway through your pregnancy, you probably do not have a lot of stomach-sleeping left, so enjoy it while you can.</p>
<p>Back sleeping gets more of the negative press. The theory is that as the uterus get larger (beyond 20 weeks or so), it can compress an important blood vessel when you are lying on your back. If this decreases mom’s blood pressure, it could reduce blood flow to the placenta and baby. This worry stems from the fact that some women feel faint when lying on their backs during pregnancy. What is the more relevant question for you is whether there is any evidence that this actually has risks for the baby. If you wake up on your back, should you worry?</p>
<p>The answer, not especially helpfully, is probably not.</p>
<p>In one <a href="http://www.ncbi.nlm.nih.gov/pubmed/1988881">very good study</a>, researchers had pregnant women lie on their backs, and they measured blood pressure and the blood flow to the uterus. They found that lying down has no particularly bad impact on blood flow. A couple of women in that study became uncomfortable but felt better when they changed positions. The authors conclude that some women might be uncomfortable sleeping on their backs, but if you are not one of them, you should feel fine about it.</p>
<p>This paper was included as part of a <a href="http://www.ncbi.nlm.nih.gov/pubmed/17915068">review article</a> about the topic, which ended by saying that pregnant women should be encouraged to sleep in any position they find comfortable.</p>
<p>I say “probably” in my answer above because last year a <a href="http://www.bmj.com/content/342/bmj.d3403">new study</a> came out that did show a link between maternal sleep position and stillbirth. The researchers interviewed women who had recently had a stillbirth and found that relative to similar women who had healthy babies, the women who had stillbirths were more likely to have slept on their backs. This study wasn’t perfect—it’s small and the researchers were looking at a lot of outcomes, not just stillbirth—but the effects were statistically significant and large (back-sleeping doubled the risk of stillbirth).</p>
<p>So we're left in a frustrating but common position: More research is needed. In the interim, it's not clear what the right conclusion is. Sleeping on your left side, which is encouraged because it does not risk artery compression, is unlikely to be bad, so that's a good option if you can manage to get some rest that way.</p>Fri, 06 Sep 2013 14:01:00 GMThttp://www.slate.com/blogs/expecting_better/2013/09/06/deli_meats_and_sleeping_on_your_back_while_pregnant_are_either_ok.htmlEmily Oster2013-09-06T14:01:00ZDouble XPlease Can I Have a Turkey Sandwich and Sleep on My Back While Pregnant?238130906001pregnancyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/09/06/deli_meats_and_sleeping_on_your_back_while_pregnant_are_either_ok.htmlfalsefalsefalseDo you really have to forgo turkey sandwiches while pregnant?Please Can I Have a Turkey Sandwich and Sleep on My Back While Pregnant?Photo by leedsn/ShutterstockGo ahead.The Best Method for Getting Pregnanthttp://www.slate.com/blogs/expecting_better/2013/09/04/ovulation_tracking_to_get_pregnant_should_you_chart_your_temperature_check.html
<p>We all know people who decide to stop using birth control, just let things happen naturally, and are pregnant two weeks later. I wish I could say I approached getting pregnant with this relaxed attitude. In reality, I came to it with the grim determination of someone training for a marathon. Yeah, there might be some endorphins along the way, but basically we’re just going for the finish line.</p>
<p>Consistent with how I’d approach any goal-oriented activity, I wanted to make sure I was doing everything I could to accomplish the task. So I started taking my temperature every morning. This is an old technique for charting fertility; it relies on the fact that morning body temperature is slightly higher in the second half of the menstrual cycle, after ovulation, than the first half. By recording temperatures, you can in principle learn which days of the month are most fertile for you.&nbsp;</p>
<p>In the books I read, the temperature charts looked beautiful: low temperatures at the start of the month, a huge increase one day, and then high temperatures the rest of the month. My charts, in contrast, looked like a kindergarten art project. I eventually did get pregnant, but no thanks to the thermometer. When I then sat down a few months later to write <a href="http://www.amazon.com/gp/product/1594204756/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=1594204756&amp;linkCode=as2&amp;tag=slatmaga-20"><em>Expecting Better</em></a><em>, </em>I wondered whether I was the only one who couldn’t get this right.&nbsp;</p>
<p>There are three commonly used methods for detecting ovulation: charting your temperature, checking your cervical mucus, and (slightly higher tech) peeing onto one of those ovulation tracker sticks. You can, of course, combine these techniques, and naturally there&nbsp; is an <a href="http://www.slate.com/articles/technology/technology/2013/08/new_fertility_app_glow_it_wants_to_know_absolutely_everything_about_you.html">app</a> for that. In principle, all three approaches work. The question is how they work in practice for the average woman.&nbsp;</p>
<p>We can learn something about this from a study that appeared in the journal <a href="http://www.ncbi.nlm.nih.gov/pubmed/10560997"><em>Fertility and Sterility</em></a><em> </em>in the late 1990s<em>. </em>Women in the study used these fertility-charting methods, and researchers also detected the actual day of ovulation with ultrasound.</p>
<p>The temperature charting method did OK, but I wasn’t alone in finding it not perfect. As used by the women in the study, it accurately identified the day of ovulation about 30 percent of the time. Another 30 percent of the time this method pointed to ovulation one day before it actually occurred. The day-before ovulation is also a good time for getting pregnant, so if you had sex on the date indicated by the temperature charting, 60 percent of the time you would manage to time sex on one of your two most fertile days of the month.</p>
<p>Results for the second technique, checking the quality of cervical mucus (which, when you are ovulating, is clear and stretchy—it’s often called “egg white mucus”), were about as good. In this same study, checking mucus detected the date of ovulation 50 percent of the time. In <a href="http://www.ncbi.nlm.nih.gov/pubmed/12413617">another study</a> with a similar design, but focused only on cervical mucus, this technique identified the day of ovulation in about 34 percent of cases and the day before ovulation in another 25 percent of cases.</p>
<p>Finally, we arrive at the ovulation pee sticks. These work great. In the <em>Fertility and Sterility </em>study they detected ovulation 100 percent of the time. The downside, of course, is that <a href="http://www.amazon.com/gp/product/B002VLYAOI/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=B002VLYAOI&amp;linkCode=as2&amp;tag=slatmaga-20">they are expensive</a>.</p>
<p>So, how big a deal is it to detect ovulation? Answer: It matters. From very <a href="http://www.ncbi.nlm.nih.gov/pubmed/7477165">detailed data</a> on couples—including exactly when they had sex and whether they conceived—we know that pregnancy is only possible in the five or six days leading up to and including ovulation. This suggests that you’ve got to get the timing right, and if you do, the odds are pretty good. Pregnancy rates are 30 percent for sex on the day before or day of ovulation, versus 10 percent five days before. No one in the aforementioned study got pregnant having sex more than five days before ovulation.</p>
<p>So should you lay back and leave your pregnancy to chance, or track, measure, and chart? Depends on your time frame, I suppose. But done right, if you want to have the best shot at getting pregnant, shell out for the pee sticks.</p>Wed, 04 Sep 2013 12:30:00 GMThttp://www.slate.com/blogs/expecting_better/2013/09/04/ovulation_tracking_to_get_pregnant_should_you_chart_your_temperature_check.htmlEmily Oster2013-09-04T12:30:00ZDouble XThe Best Method for Getting Pregnant (in Addition to the Obvious)238130904001pregnancyFamilyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/09/04/ovulation_tracking_to_get_pregnant_should_you_chart_your_temperature_check.htmlfalsefalsefalseThe best method for getting pregnant (in addition to the obvious).The Best Method for Getting Pregnant (in Addition to the Obvious)Photo by Piotr Adamowicz/ShutterstockDoes your body temperature cycle make a pretty chart?How to Know Which Pregnancy Studies Are Legithttp://www.slate.com/blogs/expecting_better/2013/08/28/pregnancy_issues_when_looking_for_answers_how_to_know_which_studies_warrant.html
<p>Most weeks, CNN Health or the <em>New York Times</em> Science section (or <strong><em>Slate</em></strong>!) reports on another study about health. Within the past couple weeks there was one about how <a href="http://www.businessinsider.com/how-too-much-coffee-can-kill-you-2013-8">four cups of coffee a day kills</a> you and one on which brands of adult beverages are most likely to result in a <a href="http://well.blogs.nytimes.com/2013/08/19/beers-implicated-in-emergency-room-visits/?ref=health&amp;_r=2">trip to the emergency room</a> (answer: malt liquor).</p>
<p>A question that comes up again and again in reading these, and came up all the time when I was writing my book on pregnancy, is how to know which studies warrant our attention.</p>
<p>The gold standard in medicine, and in other fields, is the randomized controlled trial. In a study like this, participants are divided into two (or more) groups randomly, and each is told to do something different. In a drug study, one group takes a drug and the other does not. Because the groups are randomly selected, on average they are similar before the study. So if the researchers see differences after the study, they can be confident the differences are due to the treatment.</p>
<p>Even in a randomized study, there are limitations. No research study is run on the entire population of the world. What we learn from these studies is the impact of the treatment on average, not on every individual.</p>
<p>So if you are approaching a health decision based on data from a randomized study, that’s great. But the majority of the time, especially in public health where I looked for data on pregnancy, the studies aren’t randomized. In 2012, the <em>American Journal of Public Health</em> published 128 papers—only 14 of them were randomized. &nbsp;</p>
<p>What we get instead are observational studies, which also compare individuals who engage in different behaviors. The difference, though, is that these individuals choose to engage in these behaviors on their own—and if differences among people influence their choice of behavior, it may be those differences, not the behavior itself, that changes their outcomes.</p>
<p>Let’s consider a particular example, drawn from pregnancy (since this is, after all, a pregnancy blog). When I came to look at the issue of caffeine, I found that, at least in evaluating the relationship with miscarriage, there were no randomized studies. So I turned to observational studies.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/18221932">One</a> that I summarize in <a href="http://www.amazon.com/gp/product/1594204756/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=1594204756&amp;linkCode=as2&amp;tag=slatmaga-20">my book</a> is from the <em>American Journal of Obstetrics and Gynecology, </em>published in 2008. The paper compares women who drink no caffeine to those who drink two cups a day or more and analyzes the risk of miscarriage (the researchers also included an intermediate group, but for now we’ll think about the simple comparison). Table 1 of this paper summarizes the characteristics of women in these different caffeine groups. Here’s a subset:</p>
<p>Clearly, there are big differences across these groups other than how much caffeine they drink. The coffee drinkers are older, more likely to be white, poorer on average, and more likely to smoke. Smoking and age, in particular, are linked to miscarriage. So is it the coffee? Or is it the smoking?</p>
<p>The crucial element of evaluating these studies is to figure out how big these differences really are and how much they matter. It’s common in studies like this to show the impacts of the treatment—in this case, caffeine—after adjusting for these controls. This adjustment is important but also incomplete. In the above study, for instance, the authors controlled for whether the household income was more or less than $50,000, but that’s only a crude measure. It is hard to know whether better controls—more detail about income— would make more of a difference. &nbsp;</p>
<p>What does this mean, in general, when we’re faced with these studies? How can we evaluate them? One thing to start with is always be a little skeptical. But a bit more concretely, here are two tips:</p>
<p>1. Look at how different the groups are on factors such as age, education, and so on. All else equal, the more similar the groups look, the better.</p>
<p>2. Look at how complete the data is. A lot of media reports say a study is “adjusted for socio-demographics.” How effective this is depends on how comprehensive the variables on demographics are. A study using data that details exactly how much education someone has, and exactly their income will be able to adjust more completely for this issue than one where all the researchers observe is whether someone completed high school or not.</p>
<p>If you use these criteria, you’ll quickly realize that some studies are much, much better than others. And while no single study is going to be enough to close the book on any issue, thinking critically about these possible problems may sometimes lead you to decide a study doesn’t have much information at all. Not to mention allow you to drink coffee.</p>Wed, 28 Aug 2013 11:14:00 GMThttp://www.slate.com/blogs/expecting_better/2013/08/28/pregnancy_issues_when_looking_for_answers_how_to_know_which_studies_warrant.htmlEmily Oster2013-08-28T11:14:00ZDouble XHow to Know Which Pregnancy Studies Are Legit238130828001pregnancyFamilyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/28/pregnancy_issues_when_looking_for_answers_how_to_know_which_studies_warrant.htmlfalsefalsefalseLooking for the best answers to your pregnancy questions? Here's how to know which studies are legit.How to Know Which Pregnancy Studies Are LegitPhoto by wavebreakmedia/ShutterstockFamiliar?Exercise During Pregnancy: How Much Is Too Much?http://www.slate.com/blogs/expecting_better/2013/08/26/exercise_during_pregnancy_how_much_is_too_much.html
<p>I got a lot of great reader questions last week, and about every third one was on exercise. Obviously, <strong><em>Slate </em></strong>has many very fit readers, since most questions focused on whether high-intensity exercise is a problem. A couple of examples:</p>
<p><strong>From Clara:</strong></p>
<p><em>I am a pretty fit person (I run, I do Pilates, etc.) but in all of my pregnancies I have toned down my workouts while pregnant, in large part because running just isn't comfortable.&nbsp;</em></p>
<p><em>But, I've noticed a lot of pregnant women continuing very rigorous exercise (boot-camp-style classes) throughout most of their pregnancy. What is the general thinking on this? Is it safe to continue with a high-intensity workout, or should women be toning it down? Is the risk to the unborn child or to the body of the woman carrying the child?</em></p>
<p><strong>From Jennifer:<em>&nbsp;</em></strong></p>
<p><em>I'm hoping that in one of your future blogs you can address the topic of exercise. What is forbidden and what isn't? How much exercise is too much?</em></p>
<p><em>I ask this because I am an avid runner. When I was pregnant with my first child, I continued to run up until my third trimester. Granted, my distances weren't so great, and I was getting slower each time I ran, but still I continued. My doctor approved of my exercise. I ended up giving birth to a healthy baby boy. I would even go as far to say that maintaining an exercise routine during my pregnancy lessened the pain of labor and childbirth.&nbsp;</em></p>
<p><em>That being said, I got sooooo many dirty looks on my runs!</em></p>
<p>I can’t say I relate to Clara and Jennifer—I spent my pregnancy mostly focused on whether I really HAD to walk on the treadmill for 30 minutes a day or could instead just vegetate in front of reality TV. But I did look into the issue of intense exercise, just in case I had a sudden burst of energy. (I never did.)</p>
<p>The concern about exercise comes, at least in large part, from a few studies that show that women who do a lot of physical labor at their jobs have more pregnancy complications (preterm birth, for example) than women who don’t. One example <a href="http://jech.bmj.com/content/58/5/395.long">is this study</a>, which shows that women who stand for more than six hours a day at their job are about 1.25 times as likely to have a preterm delivery as those who do not. The issue with this study is that women who have jobs that require them to stand a lot also tend to be different in other ways (less educated, for example), which also relate to preterm birth.</p>
<p>Better is to look at studies of exercise that are randomized, meaning that half of the women in the study are randomly selected for exercise encouragement. Studies like this exist, although they are mostly small. They generally consider what happens when you encourage women to do 30 or so minutes of aerobic exercise three to five times a week—basically, about what we are all trying to fit in.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/16855953">The findings</a> suggest that there is little impact: no change in preterm birth rates, gestational age, frequency of cesarean sections, or fetal growth. There is no evidence of a difference in baby Apgar scores or in the length of labor. The studies also don’t find any negative impacts on the mom.</p>
<p>This suggests that if you’re engaging in 30 minutes of standard aerobic exercise in pregnancy, that’s fine to continue. However, there <em>is </em>some evidence that exercising really hard during pregnancy could (very temporarily, during the period of exercise) compromise blood flow to the baby. In <a href="http://www.ncbi.nlm.nih.gov/pubmed/21393257">one study</a> of six Olympic-level athletes, researchers found that when women exercised so hard that they pushed their heart rate to more than 90 percent of their maximum heart rate, there was a decrease in the fetal heart rate below what is considered normal. This was temporary—when the women stopped the exercise the heart rate returned to normal. However, there is a concern that repeated fetal distress—if exercise like this occurs every day during a pregnancy—could have negative consequences.</p>
<p>So how to know when you are exercising too hard? Your maximum heart rate is around <a href="http://www.mayoclinic.com/health/target-heart-rate/SM00083">220 minus your age</a>. If you’re pregnant at 30, this is 190 beats per minute. The evidence from elite athletes therefore suggests you should stay under 90 percent of that, or about 170 beats per minute. If you think you may be coming close to this, by all means get a heart monitor and try it on a few runs. If you find you’re not coming close, you can start leaving it at home.</p>
<p>Got more questions? Don’t forget: I’m taking them at <a href="mailto:expectingbetter@gmail.com">expectingbetter@gmail.com</a> for future posts! (I will use your name unless you specify otherwise, and please check out&nbsp;<strong><em>Slate</em></strong>'s&nbsp;<a href="http://www.slate.com/articles/briefing/slate_user_agreement_and_privacy_policy/2012/12/slate_s_discussion_and_submission_guidelines.html">submission guidelines</a>&nbsp;before you write in.)</p>Mon, 26 Aug 2013 12:30:00 GMThttp://www.slate.com/blogs/expecting_better/2013/08/26/exercise_during_pregnancy_how_much_is_too_much.htmlEmily Oster2013-08-26T12:30:00ZDouble XPregnant Women In Boot Camp Classes? How Much Exercise Is Too Much?238130826001excercisepregnancyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/26/exercise_during_pregnancy_how_much_is_too_much.htmlfalsefalsefalseHow much exercise is too much when you're pregnant?Pregnant Women In Boot Camp Classes? How Much Exercise Is Too Much?Photo by Ljupco Smokovski/Shutterstock<em><strong>Slate</strong></em> readerYour Doctor Offers to Induce Labor. Should You Say Yes?http://www.slate.com/blogs/expecting_better/2013/08/21/labor_inductions_you_want_to_get_the_baby_out_but_should_you_induce_before.html
<p>A new study came out last week <a href="http://archpedi.jamanetwork.com/article.aspx?articleid=1725449">linking autism to labor induction</a>. I will not get into the weeds right now on that particular study (although here is <a href="http://www.redwineandapplesauce.com/2013/08/13/that-link-between-autism-and-labor-inductionaugmentation-yea-take-another-look/">one</a> very critical take), but it got me thinking again about labor induction, a topic that I cover at some length in <em><a href="http://www.amazon.com/gp/product/1594204756/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=1594204756&amp;linkCode=as2&amp;tag=slatmaga-20">Expecting Better</a>.</em></p>
<p>When I was 39 weeks pregnant, my doctor offered to schedule an induction at my due date. This is common now, although that wasn’t always the case. In 1990, fewer than 10 percent of births followed medical induction of labor; by 2009, this number had risen to 25 percent. This increase has occurred across the board, not just for babies who are overdue. In 1990, only 7 percent of births at 39 weeks of pregnancy were induced, but 23 percent were induced by 2009.</p>
<p>Sometimes, labor is induced for medical reasons—the baby isn’t doing well or a condition threatens mom’s health. This, obviously, makes a lot of sense, and we are lucky to have the option. But this wasn’t the case for me; my doctor was effectively offering an elective induction: I could choose to have the baby at 40 weeks, rather than wait for her to arrive on her own. And by 39 weeks I was definitely tired of being pregnant, and Penelope was plenty big. But still I said no, and here are the two reasons why.</p>
<p>First, the use of pitocin—the primary method of induction—may increase pain in labor. For anecdotal evidence on this all you have to do is go online: Chat boards are full of women who have had spontaneous labor and an induction and report the latter was more unpleasant. My mother had three children, all without an epidural, and reported that labor after she was induced with my youngest brother was the worst, despite the fact that he was the third kid. Going beyond anecdotes, <a href="http://www.ncbi.nlm.nih.gov/pubmed/19821304">researchers find</a> that women who are induced with pitocin are more likely to use an epidural; increased use of pain relief probably points to increased pain (at least before the epidural is administered!).</p>
<p>Second, there is both <a href="http://www.ncbi.nlm.nih.gov/pubmed/14583960">direct and indirect evidence</a> that induction can increase the risk of a cesarean section. This seems to be most true when pitocin is used alone. Of course, C-sections are safe and common, but recovery from them still tends to be harder than recovery from a vaginal delivery.</p>
<p>These concerns are there for any induction—before or after 40 weeks. I was even more wary of pre-due-date induction. Some women like this idea—37 weeks is full term, so why not get the baby out already?— but it is really not smart if not medically indicated.</p>
<p>It is true that babies who come on their own at 37 weeks do pretty much just as well as those who arrive on their own at 40 weeks. One good way to measure this is with something called the Apgar score. This is a number from zero to 10 that measures how well your baby is doing at birth—about 80 percent of babies get an Apgar of nine or 10, which means the baby is doing well, and a score of seven or below typically indicates some distress.</p>
<p>Among babies born on their own—no induction—at 37 weeks, about 2.4 percent of them have a low Apgar score. Among those born on their own at 40 weeks, this is about 2.3 percent; the difference is very small. But when we look at <em>induced</em> births, we see (slightly) larger differences. For babies induced at 40 weeks, again the share with low Apgar scores is 2.3 percent, but for babies induced at 37 weeks, it’s about 3 percent. This difference is small in magnitude but statistically significant.</p>
<p>This basic point is consistent with something that the American College of Obstetricians and Gynecologists <a href="http://www.pqcnc.org/documents/sivbdoc/sivbeb/2ACOG2009PracticeBulletin107InductionofLabor.pdf">has been saying</a> for a long time: that elective inductions should not be performed before 39 weeks. Basically, some babies are ready at 37 weeks, but that does not mean they all are.</p>
<p>Does this mean you should say no to an induction for medical reasons? No. But it may mean that it’s a good idea to stick it out for a few more days, to give your kid a chance to arrive on his or her own time.</p>
<p>Got more questions? Don’t forget: I’m taking them at <a href="mailto:expectingbetter@gmail.com">expectingbetter@gmail.com</a> for future posts! (I will use your name unless you specify otherwise, and please check out&nbsp;<em><strong>Slate</strong></em>'s&nbsp;<a href="http://www.slate.com/articles/briefing/slate_user_agreement_and_privacy_policy/2012/12/slate_s_discussion_and_submission_guidelines.html">submission guidelines</a>&nbsp;before you write in.)</p>Wed, 21 Aug 2013 14:00:00 GMThttp://www.slate.com/blogs/expecting_better/2013/08/21/labor_inductions_you_want_to_get_the_baby_out_but_should_you_induce_before.htmlEmily Oster2013-08-21T14:00:00ZDouble XYour Doctor Offers to Induce Labor. Should You Say Yes?238130821001pregnancyFamilyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/21/labor_inductions_you_want_to_get_the_baby_out_but_should_you_induce_before.htmlfalsefalsefalseYour doctor offers to induce labor. Should you say yes?Your Doctor Offers to Induce Labor. Should You Say Yes?Photo by sharpshutter/ShutterstockAll you want to do is get the baby out. Give it a few days.Against Bed Rest&nbsp;&nbsp;&nbsp;http://www.slate.com/blogs/expecting_better/2013/08/19/bed_rest_during_pregnancy_doctor_s_orders_to_curb_premature_labor_but_there.html
<p>As many as 20 percent of women are prescribed bed rest for a period of time during their pregnancies, ranging from a few days to multiple months. Usually the concern is threatened premature labor, which could result from a specific condition or occur without warning.</p>
<p>So why bed rest? Well, it seems logical—surely laying down and not jostling so much is a good idea! And if you know someone who has been on bed rest and went on to have a healthy, full-term delivery, it may look like it worked. Many women who are put on bed rest go on to have their babies at a normal time.&nbsp;</p>
<p>But, and I cannot stress this enough, <strong><em>that is not evidence that it works</em></strong>. We don’t know what would have happened if those women engaged in normal activities. In fact, there is no compelling evidence to suggest that bed rest is effective at preventing preterm labor.</p>
<p>This is most conclusively demonstrated by randomized studies—the gold standard in medical evidence—where some women are selected to be on bed rest and others are selected not to be. Because the selection is random, we can be confident in attributing any differences across the groups to bed rest.</p>
<p>Consider <a href="http://www.ncbi.nlm.nih.gov/pubmed/14974024">one study</a> of 1200 pregnant women—400 of them were put on bed rest, and 800 were not. In the end, 7.9 percent of the bed rest group had premature babies, versus 8.5 percent of the non-bed-rest group, a difference that was so small that it could have been due to chance. Other randomized evidence on twin and triplet pregnancies (which often result in bed rest prescriptions) demonstrates the same thing. This review article <a href="http://www.ncbi.nlm.nih.gov/pubmed/21425272">from 2011</a> says it bluntly: “There are no complications of pregnancy for which there are demonstrated benefits of bed rest.”</p>
<p>So, what should we do with this information? Well, we need more randomized evidence, with larger studies. But, at the moment, we simply have no evidence suggesting bed rest works in improving outcomes for babies, so we should stop sending pregnant women to their beds.</p>
<p>You might prefer to think “better safe than sorry,” but bed rest actually has some significant negative consequences. Full bed rest is defined as one to two hours of activity per day, with the rest of the time spent in bed. No work, no running after your toddler, no setting up the baby's room, no making dinner, no exercise, no nothing. This has serious downsides for your family and, for women who work, their jobs. Studies cite financial strain on families when women are put on bed rest, even if they don’t work, because of the need to get someone else to help around the house.</p>
<p>Plus, there are actually <a href="http://www.ncbi.nlm.nih.gov/pubmed/21425272">medical risks to bed rest</a>—bone loss, muscle atrophy, weight loss and, in some studies, decreased infant birth weight.<sup>&nbsp; </sup>There is some evidence to suggest that bed rest increases the risk of<a href="http://www.ncbi.nlm.nih.gov/pubmed/10819836"> blood clots</a> (to avoid this, women on bed rest sometimes wear compression socks).</p>
<p>Usually when we consider a medical treatment with no demonstrated benefits and large demonstrated risks, we conclude that it’s a bad idea. In fact, that’s the strong consensus in the medical literature. Last year the American Congress of Obstetricians and Gynecologists—the official source for pregnancy rules and regulations—issued <a href="http://www.ncbi.nlm.nih.gov/pubmed/22617615">a bulletin</a> suggesting that bed rest was not, in fact, a recommended treatment for premature labor.</p>
<p>And, even more surprising, many doctors seem to know this is a waste of time. A <a href="http://news.sego.es/PDF/reposocama-ap-amjobst.pdf">2009 article</a> that reported on a survey of practicing OBs showed that more than half of them say that bed rest has “no” or “minimal” benefit.<sup>&nbsp; </sup>And yet: 90 percent of these doctors reported prescribing bed rest!</p>
<p>It would seem that this is one of those areas where the conventional recommendation has hung on despite evidence suggesting it's not just ineffective but damaging. There may be unusual situations in which bed rest is a good idea, but the medical literature hasn’t found any of them. So what should you do if your doctor suggests bed rest? You should almost certainly question him or her. Do they really think it will help? It may be hard to push back if they insist you rest, but you should at least be sure they are aware of the evidence to the contrary.</p>Mon, 19 Aug 2013 12:00:00 GMThttp://www.slate.com/blogs/expecting_better/2013/08/19/bed_rest_during_pregnancy_doctor_s_orders_to_curb_premature_labor_but_there.htmlEmily Oster2013-08-19T12:00:00ZDouble XAgainst Bed Rest: There's No Proof That It Works.238130819002pregnancyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/19/bed_rest_during_pregnancy_doctor_s_orders_to_curb_premature_labor_but_there.htmlfalsefalsefalseThere's no proof that bed rest works. So why do doctors keep sending women to their beds?Against Bed Rest: There's No Proof That It Works.Photo by Eternalfeelings/ShutterstockMore stressful than it looksIntroducing Expecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/19/expecting_better_a_new_blog_about_pregnancy_by_the_numbers.html
<p>You’re pregnant. You’re at Starbucks, minding your own business, waiting for your iced skinny vanilla latte. “I hope that’s decaf!” says the lady behind you. Resisting the urge to pour the drink all over her head, you stare at her, stone-faced, and leave the store.&nbsp;</p>
<p>Now imagine another scenario. Same store, same latte, same lady. But this time you’re ready. Rather than just staring and leaving, you calmly explain to her the many, many studies that show that caffeine, in moderation, is fine for your baby. She apologizes profusely, and you leave triumphant.</p>
<p>If that sounds good, this is the blog for you.&nbsp;</p>
<p>My new book—<a href="http://www.amazon.com/gp/product/1594204756/ref=as_li_ss_tl?ie=UTF8&amp;camp=1789&amp;creative=390957&amp;creativeASIN=1594204756&amp;linkCode=as2&amp;tag=slatmaga-20"><em>Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong, and What You Really Need to Know</em></a>—is out tomorrow. It’s about pregnancy, but doesn’t include any sections on how big your baby is each week (or what fruit size it compares to) or what emotions you’ll be feeling. Instead, you’ll find information you can use to make better decisions. &nbsp;</p>
<p>Can I have a glass of wine? Coffee? How much weight can I gain? Should I get an epidural? When is the baby coming out, anyway?</p>
<p>The book is decidedly not about recommendations. It’s about information. You can find plenty of books that tell you, “Go ahead, have a glass of wine.” I do say that, but I also explain <em>why</em> I came to that conclusion, with citations to the medical literature, providing you with ammunition for the nosy Starbucks ladies.</p>
<p>I’m an economist; my business is decision-making and data. When I got pregnant, I used the tools from my job to think about my pregnancy. It didn’t occur to me to do it any other way.</p>
<p>So what’s going to be on this blog? For the next month or so, I’ll give you a few tidbits from the book, and a few things that didn’t make it in. I’d also like to hear from you. Got a burning question about pregnancy? Send it along to <a href="mailto:expectingbetter@gmail.com">expectingbetter@gmail.com</a>. (I’ll use your name unless you specify otherwise, and please check out&nbsp;<em><strong>Slate</strong></em>'s&nbsp;<a href="http://www.slate.com/articles/briefing/slate_user_agreement_and_privacy_policy/2012/12/slate_s_discussion_and_submission_guidelines.html">submission guidelines</a>&nbsp;before you write in.) I’ll pick some favorites, do the research for you, and post the answer. Think of me as your own personal pregnancy concierge.</p>
<p>So, sit back, enjoy that caffeinated latte, and get ready to expect better.</p>
<p><strong><em>First up: <a href="http://www.slate.com/blogs/expecting_better/2013/08/19/bed_rest_during_pregnancy_doctor_s_orders_to_curb_premature_labor_but_there.html">The persistent myth of bed rest.</a></em></strong></p>Mon, 19 Aug 2013 09:30:00 GMThttp://www.slate.com/blogs/expecting_better/2013/08/19/expecting_better_a_new_blog_about_pregnancy_by_the_numbers.htmlEmily Oster2013-08-19T09:30:00ZDouble XIntroducing Expecting Better, a New Blog About Pregnancy By the Numbers238130819001pregnancyEmily OsterExpecting BetterExpecting Betterhttp://www.slate.com/blogs/expecting_better/2013/08/19/expecting_better_a_new_blog_about_pregnancy_by_the_numbers.htmlfalsefalsefalseIntroducing Expecting Better, a new blog about pregnancy by the numbers.Introducing Expecting Better, a New Blog About Pregnancy By the NumbersPhoto by Zurijeta/ShutterstockCaffeinated, but thanks for asking